Example (1). A is the owner of 6 highway motor vehicles, each of which has a taxable gross weight in excess of 55,000 pounds. None of these 6 vehicles are agricultural vehicles. The vehicles are placed in use during July 1984. Because of the nature of his business, A reports on the first Form 2290 filed after June 30, 1984, that he reasonably expects that none of the vehicles will be used for more than 5,000 miles on public highways. Accordingly, the tax imposed by section 4481(a) is suspended for A's 6 vehicles for the taxable priod July 1, 1984, through June 30, 1985.
Example (2). Assume the same facts as in example (1) except that during the month of February 1985, the use of one of A's vehicles exceeds 5,000 miles on public highways. A is liable for the full tax for the taxable period July 1, 1984, through June 30, 1985, for that vehicle at the rate set forth in § 41.4481-1(b) , and must so report on a Form 2290 filed on or before March 31, 1985, the last day of the month following the month in which the use exceeds 5,000 miles.
A highway motor vehicle is used primarily for farming purposes if more than one-half of such vehicle's use (determined on the basis of mileage) during the taxable period is for farming purposes. Further, the highway motor vehicle must be registered (under the laws of the State or States where such vehicle is required to be registered) as a highway motor vehicle used for farming purposes for the entire taxable period in order to qualify as an agricultural vehicle. See § 41.4482(a)-(1) for the definition of "highway motor vehicle". A vehicle will be considered to be registered under the laws of the State as a highway motor vehicle used for farming purposes if such vehicle is so registered under a State statute or legally valid regulations. In addition, no special tag or license plate identifying a vehicle as being used for farming purposes is required.
26 C.F.R. §41.4483-3